I'll definitely agree with what CPorter wrote but I'll add... ALWAYS bring an extra battery.
I have an extra meter for road trips (Pentax Digital Spot in the LF pack and a Pentax V Spot meter in the car). And a Gossen SBC in my MF bag -- nice for the low light situations. And an extra battery or two..
At least with LF landscape, a bad day of photography can still be a good day of exercise.